Intravascular temperature monitoring system and method

ABSTRACT

A system for monitoring one or more temperatures at a vessel wall of a vessel of a patient includes an optical fiber, an optical read-out mechanism, and a therapeutic device. The optical fiber may be deployed along an extent of the vessel and may include one or more fiber Bragg grating (FBG) temperature sensors disposed at one or more corresponding sensor locations along a length of the optical fiber. The optical read-out mechanism may be optically coupled to the optical fiber, and it may be configured to transmit light into the optical fiber and detect light reflected from the one or more FBG temperature sensors. The detected light reflected from the one or more FBG temperature sensors may encode local temperatures at each of the one or more corresponding sensor locations. The therapeutic device may be configured for performing a therapeutic procedure to or through the vessel wall.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 to U.S.Provisional Application Ser. No. 61/545,959, filed Oct. 11, 2011, theentirety of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to optical fiber-based sensor systems,and more particularly, optical fiber-based methods and apparatus formonitoring temperatures within vessels of a patient. Such monitoring maybe performed in conjunction with ablation of nerve tissue proximal ablood vessel wall of the patient.

BACKGROUND

Certain treatments require the temporary or permanent interruption ormodification of select nerve function. One example treatment is renalnerve ablation which is sometimes used to treat conditions related tocongestive heart failure. The kidneys produce a sympathetic response tocongestive heart failure, which, among other effects, increases theundesired retention of water and/or sodium. Ablating some of the nervesrunning to the kidneys reduces or eliminates this sympathetic function,which provides a corresponding reduction in the associated undesiredsymptoms.

Many nerves (and nervous tissue such as brain tissue), including renalnerves, run along the walls of or in close proximity to blood vesselsand thus can be accessed intravascularly through the walls of the bloodvessels. It is therefore desirable to provide for systems and methodsfor intravascular nerve modulation. It may be desirable to monitortemperatures intravascularly at vessel wall locations before, during,and/or after some such procedures. Minimally invasive in vivotemperature measurement may find uses in other medical contexts as well.Therefore, there remains room for improvement and/or alternatives inproviding for systems and methods for intravascular nerve modulation.

SUMMARY

The present disclosure relates to optical fiber-based sensor systems,and more particularly, optical fiber-based methods and apparatus formonitoring temperatures within vessels of a patient. In one illustrativeembodiment, a system for monitoring one or more temperatures at a vesselwall of a vessel of a patient includes an optical fiber, an opticalread-out mechanism, and a therapeutic device. The optical fiber may bedeployed along an extent of the vessel and may include one or more fiberBragg grating (FBG) temperature sensors disposed at one or morecorresponding sensor locations along a length of the optical fiber. Theoptical read-out mechanism may be optically coupled to the opticalfiber, and it may be configured to transmit light into the optical fiberand detect light reflected from the one or more FBG temperature sensors.The detected light reflected from the one or more FBG temperaturesensors may encode local temperatures at each of the one or morecorresponding sensor locations. The therapeutic device may be configuredfor performing a therapeutic procedure to or through the vessel wall.

In another illustrative embodiment, an intravascular nerve ablationsystem includes a helical structure deployed along an extent of a vesselof a patient and an optical fiber attached to the helical structure andfollowing a helical path of the helical structure. The optical fiber mayhave one or more fiber Bragg grating temperature sensors disposed at oneor more corresponding sensor locations along a length of the opticalfiber. The helical structure may maintain at least some of the one ormore FBG temperature sensors in thermal contact with a wall of thevessel.

In yet another illustrative embodiment, a method for monitoring one ormore temperatures at a vessel wall of a vessel of a patient with anoptical fiber having one or more fiber Bragg grating temperature sensorsis provided. The method includes the steps of deploying the opticalfiber along an extent of the vessel such that the optical fiber isdisposed against the vessel wall with the one or more FBG temperaturesensors in thermal contact with the vessel wall, and reading-outtemperatures detected by the one or more FBG temperature sensors with anoptical read-out mechanism configured to transmit light into the opticalfiber and detect light reflected from the one or more FBG temperaturesensors. The method may further include the step of performing atherapeutic procedure with a therapeutic device disposed within thevessel proximal to at least one of the one or more FBG temperaturesensors. The therapeutic procedure may include tissue ablation. In someinstances, a temperature measured by the at least one of the one or moreFBG temperature sensors may be used as a feedback signal for controllingthe therapeutic procedure.

The above summary of some embodiments is not intended to describe eachdisclosed embodiment or every implementation of the present disclosure.The Figures, and Detailed Description, which follow, more particularlyexemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of thefollowing detailed description of various embodiments in connection withthe accompanying drawings, in which:

FIG. 1 is a schematic view of an intravascular temperature monitoringsystem and a renal nerve modulation system in situ.

FIG. 2 is a schematic illustration of elements of an optical fiber-basedsensor system.

FIG. 3 is a schematic illustration of elements of an optical fiber-basedsensor system deployed in a vessel.

FIG. 4 is a schematic cross-sectional view of a system including asupport structure with an integrated optical fiber and a movabletherapeutic device.

FIG. 5 is a schematic illustration of a distal end of a renal nerveablation system with off-wall ablation electrodes and an opticalfiber-based sensor.

FIG. 6 is a flowchart of an exemplary optical fiber-based temperaturemeasuring method.

While the disclosure is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that the intention is not to limit the invention tothe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the disclosure.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may be indicative asincluding numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

Although some suitable dimensions, ranges and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofskill in the art, incited by the present disclosure, would understanddesired dimensions, ranges and/or values may deviate from thoseexpressly disclosed.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the disclosure. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

The present disclosure pertains at least in part to an optical method oftemperature measurement that may be performed in vivo. Temperaturemeasurements at point(s) of treatment may be useful in assessing,monitoring, and/or controlling a variety of medical procedures,including ablative procedures that rely on raising and/or lowering thetemperature of tissue to achieve ablative effects. Systems and methodsof the present disclosure may be employed in conjunction withintravascular nerve ablation procedures, but they may generally findutility in any number of other medical scenarios, as will be readilyappreciated by those skilled in the art.

Nerves that lie in proximity to blood vessels often run along the lengthof a section of a blood vessel. Nerves are difficult to image usingstandard imaging techniques such as radiography. Therefore, it may bedesirable to apply the ablation or other nerve modulation procedure atdifferent radial locations on the vessel wall to achieve ablation aroundthe complete circumference of the vessel wall. It may also be desirableto apply the procedure at different longitudinal locations so as toavoid weakening or otherwise affecting the vessel wall along a singlecircumferential section. Systems and methods of the present disclosuremay be employed to make temperature measurements proximal to ablationtreatment locations as described.

By way of a general introduction and orientation, FIG. 1 is a schematicview illustrating a system for monitoring one or more temperatures at avessel wall of a vessel of a patient, as well as a renal nervemodulation system. In some illustrative embodiments, the temperaturemonitoring system and nerve modulation system may be considered parts ofa single integrated system.

The temperature monitoring system includes an optical fiber 10 thatincludes one or more fiber Bragg grating (FBG) temperature sensors (notshown in FIG. 1) disposed at one or more corresponding sensor locationsalong a length of the optical fiber. At a proximal end, the opticalfiber 10 may be optically coupled to an optical read-out mechanism 12.The optical fiber 10 may be attached to and/or integrated with a supportstructure 14. Support structure 14 may be deployed within at least onevessel of a patient along an extent of the vessel, where it maysubstantially fix the optical fiber 10 within the vessel. As suggestedschematically in FIG. 1, at a distal region 16 the optical fiber 10 maybe deployed along an extent of the vessel in a helical path, althoughother deployment paths are contemplated. The support structure 14 may bedeployed in the same helical path as optical fiber 10, although this isnot necessary, even in cases where the optical fiber is deployed in ahelical path.

FIG. 1 illustrates elements of a renal nerve modulation system which maybe used in concert with the temperature monitoring system, althougheither system may be practiced independently of the practice or presenceof the other system. The renal nerve modulation system may include anelongate conductor 18, which may be coupled to a movable ablation tip(not shown) in the distal region 16. Conductor 18 may be coupled to anablation controller 20, which may supply electrical energy to themovable ablation tip in distal region 16. Return electrode patches 22optionally may be supplied on the legs or at another conventionallocation on the patient's body to complete the circuit.

FIG. 2 is a schematic illustration of elements of an optical fiber-basedsensor system 200, which may share features with the temperaturemonitoring system of FIG. 1. System 200 includes an optical fiber 202,which may be optically coupled to an optical read-out mechanism 204.Optical fiber includes one or more fiber Bragg gratings (FBGs)206′-206″″ (collectively, 206). FIG. 2 is a simplified, schematicillustration and does not necessarily depict all of the technicalfeatures of an optical fiber with FBGs, as would be understood by one ofordinary skill in the art. For example, optical fiber 202 may include acore, cladding, and any other suitable layers, such as a buffer coating,protective housing, etc. Fiber Bragg gratings of the present disclosure,such as FBGs 206 of optical fiber 202, may be formed by any suitablemethod, such as via two-beam interference, phase or photo masking,point-by-point writing by laser, and so on.

A FBG generally may include variations in refractive index in the coreof the fiber. The refractive index variations may form awavelength-specific grating mirror that reflects essentially all or aportion of the light at a specific reflection wavelength, while allowingthe balance of light propagating in the fiber to pass. The reflectionwavelength of a FBG may shift from its nominal value due to localconditions of the optical fiber at the FBG, such as (but not necessarilylimited to) temperature and strain. Temperature and/or strain may eachaffect the refractive index and/or grating period of the FBG, resultingin a reflection wavelength shift. This effect may be exploited to form aFBG sensor. While a FBG may generally respond (in wavelength shift) toboth temperature and strain, a FBG may be packaged (e.g., housed) inorder to modulate the physical conditions observed at the FBG. Forexample, a FBG may be packaged in order to decouple the FBG frombending, tension, compression, torsion, or other forces. With a nearlynegligible temperature coefficient of expansion of the fiber (for aglass fiber), changes in reflection wavelength for a FBG so-packaged maybe attributed primarily to a change in refractive index of the fibercaused by temperature changes. In FIG. 2, packaged FBG sensors arerepresented by 208′-208″″.

In another sensor example, a FBG may be packaged in such a way that thepackaging or housing couples changes in pressure into stress in thefiber, leading to a predictable shift in reflection wavelength. Othersensors are contemplated. A FBG chemical sensor, for example, mayinclude a FBG housing incorporating a chemically-sensitive substrate. Ingeneral, any physical mechanism that translates a change in a physicalquantity into a change in FBG reflection wavelength may potentially beused as the basis for a FBG sensor. Multiple FBG sensors (e.g.,208′-208″″) may be manufactured on a single optical fiber (e.g., 202)such that each FBG sensor has a unique reflection wavelength. Suchwavelength division multiplexing makes it possible to differentiatebetween reflection signals from a plurality of FBG sensors 208′-208″″ ona single optical fiber 202. To avoid ambiguity in interpreting FBGreflection signals, it may be desirable to fabricate each FBG to reflectwithin its own dedicated wavelength band wide enough to accommodatephysically-induced reflection wavelength shifts (that encode signalinformation) as well as the intrinsic non-zero width of the non-shiftedreflection distribution. Typically, FBG temperature sensors may beallocated an approximately 1 nm wide range, while FBG strain sensors maybe allocated an approximately 5 nm wide range. Wider or narrower rangesmay be employed, as appropriate.

FBG sensors 208′-208″″ having unique reflection wavelengths may beformed at distinct locations along optical fiber 202, such that eachparticular reflected wavelength may then correspond to a specific sensorlocation along the optical fiber.

In some cases, shifts in reflection wavelength from multiple FBG sensorsmay be interpreted in combination to arrive at a physical measurement.For example, a temperature reading from a FBG temperature sensor may beused to calibrate a pressure reading from a FBG pressure sensor, whichby itself may be sensitive to both temperature and pressure changes. Inthe present disclosure, a FBG sensor may incorporate one or more fiberBragg gratings to achieve measurement of a physical quantity.

A device such as optical read-out mechanism 204 (and 12 of FIG. 1) maybe employed to measure the wavelength reflected by a FBG sensor 208 ofoptical fiber 202. Optical read-out mechanism 204 may include anysuitable light source 210 which may transmit light into the opticalfiber 202 via an optical coupler 212. While optical coupler 212 isillustrated schematically to suggest a partially-reflective mirror orbeam-splitter, any suitable optical coupler may be used. Lightpropagates down the optical fiber 202 and is selectively reflected byone or more fiber Bragg gratings at their specific reflectionwavelengths. The specific reflection wavelengths may encode informationabout conditions at the FBG sensor 208, such as temperature, pressure,etc. Reflected light returns up the optical fiber 202 back to theoptical read-out mechanism 204, where optical coupler 212 may direct thereflected light to detector 214. Detection of light reflected by FBGsensors 208, including determination of reflection wavelengths, may thenbe interpreted by other components (not shown) of the optical read-outmechanism 204 (or external to the optical read-out mechanism) in orderto arrive at the desired quantities measured by the FBG sensors 208.

A number of different light source 210/detector 214 combinations may beemployed in an optical read-out mechanism 204. In one illustrativeembodiment, a broadband continuous light source may be used inconjunction with a dispersive element that distributes variouswavelength components of the reflected light to different locations on adetector array. In another illustrative embodiment, a tunable laser isswept over a range of wavelengths, and a photodetector measures theintensities of reflected light corresponding to the wavelengths providedby the laser at given sweep times. Other light source and detectorcombinations are contemplated, and any suitable combination of lightsource 210 and detector 214 may be employed in optical read-outmechanism 204. Some current technologies may be able to resolvereflected wavelength shifts on the order of a single picometer, whichmay translate to temperature measurement resolution on the order of 0.1degree Celsius. In some cases, temperature measurement resolutions onthe order of 0.03 degree Celsius may be achievable.

Optical fiber-based sensor systems of the present disclosure may bedeployed in vivo in any suitable manner, and may be highly compatiblewith minimally-invasive techniques. FIG. 3 is a schematic illustrationof elements of an optical fiber-based sensor system deployed in a vessel302. Elements of the system of FIG. 3 may be similar to or the same ascorresponding elements of FIGS. 1 and 2. In the illustrative embodimentof FIG. 3, component 304 is an optical fiber integrated with a supportstructure. In some other illustrative embodiments, an optical fiber maybe attached to, but not necessarily be integrated with, a supportstructure.

Support structure with integrated optical fiber 304 may be configured tocompact for delivery into the vessel 302, and expand for deployment inthe vessel. The system may include any suitable components to facilitatedelivery of optical fiber/support structure 304 to a target location invessel 302 and deployment at the target location. Suchdelivery/deployment components may include (but are not necessarilylimited to) a delivery catheter 308, which may be advanced from an entrysite to the target location, and a sheath 310, which may surroundstructure 304 and maintain it in a compact configuration duringdelivery, then be withdrawn to allow expansion and fixation of thesupport structure and optical fiber. Structure 304 may be self-expandingor may be expanded through the use of a balloon, pull wire or the like.

Any suitable material may be used for the support structure. In someillustrative embodiments, the support structure may be fabricated fromnon-conducting polymers.

Optical fiber/support structure 304 may be deployed along an extent ofvessel 302 in a helical path. In the illustrative embodiment of FIG. 3,the support structure has a helical shape, and the optical fiber isattached to the support structure and follows the helical shape of thesupport structure. In some other illustrative embodiments, the supportstructure may not have a helical shape, but the optical fiber may beattached to the support structure and itself follow a helical path. Thesupport structure may substantially fix the optical fiber within vessel302. FBG sensors 306 may be distributed along a length of the opticalfiber of component 304. The support structure may fix the one or moreFBG sensors 306 against the wall of vessel 302 such that at least one,some, or all of the one or more FBG sensors is in effective contact withthe vessel wall at its corresponding sensor location. In the context ofa FBG temperature sensor, for example, “effective contact” may meanthermal contact. In the context of a FBG pressure sensor, “effectivecontact” may mean mechanical contact.

At least some of the FBG sensors 306 may be substantiallyequally-spaced-apart along the optical fiber such that, in combinationwith the helical path along which the optical fiber is deployed, theplurality of FBG sensors are disposed around the vessel withsubstantially equal angular displacements between adjacent FBG sensors.The angular displacement between adjacent FBG sensors is schematicallyillustrated in FIG. 3 as the angle θ. The FBG sensors 306 may be spacedsuch that θ has a value of about 90, 60, 45, 30, or 120 degrees, or anyother suitable value. The helical path followed by the opticalfiber/support structure 304 may have any suitable pitch (indicated inFIG. 3 by “p”). In some illustrative embodiments, the pitch may bebetween about 5 mm to about 15 mm.

The system of FIG. 3 may also include a therapeutic device 312 forperforming a therapeutic procedure to or through the wall of vessel 302.Therapeutic device 312 may be any suitable device. In some illustrativeembodiments, therapeutic device 312 is a movable ablation tip, which maybe an RF ablation tip. Therapeutic device 312 may be attached to a cable314, which may be a conductor like elongate conductor 18 of FIG. 1.Cable 314 may also serve as a pull wire for applying mechanical force totherapeutic device 312, by which means the device may be repositioned.Support structure 304 may be configured to guide motion of thetherapeutic device 312 on a path adjacent the wall of the vessel 302along at least part of an extent of the vessel. For example, the supportstructure 304 of the present disclosure may take the form of a helical“rail” support system for guiding an optical fiber-based sensor system.

FIG. 4 is a schematic cross-sectional view of a system including asupport structure 402 with an integrated optical fiber 404, the featuresof which may be the same or similar in part or in whole with those ofthe systems of FIGS. 1 and 3. Optical fiber 404 includes at least oneFBG sensor 406. FBG sensor 406 generally may displace a largercross-sectional area than the optical fiber 404 alone. Support structure402 may integrally house the optical fiber 404 and one or more FBGsensors 406 such that the support structure, optical fiber, and FBGsensors present a substantially constant cross-section along a length ofthe support structure. A substantially constant cross-section may assistin deploying or otherwise positioning the integrated support structure402 and optical fiber 404. The support structure 402 with integratedoptical fiber 404 and FBG sensor(s) 406 may have a substantiallyconstant catheter size of about 0.5 mm, 0.8 mm, 1.0 mm, or about 1, 1.5,2, 2.5, 3, or 4 Fr. FBG sensors maybe about 1, 2, 3, or 4 mm in lengthalong the fiber. Radiopaque markers may be incorporated into the supportstructure to aid localization of the FBG sensors.

Support structure 402 may include a groove 408, protrusion, or otherstructure(s) to facilitate slidable attachment of a therapeutic device410, which may have a mating element 412 corresponding to groove 408.With such features, therapeutic device 410 may be made to slidelongitudinally along the support structure, following its path (helicalor otherwise). In such a way, the therapeutic device 410 may bepositioned in one or more treatment locations. The support structure 402may be configured such that the position of the therapeutic device 410is maintained relative to the vessel wall 414 such that the therapeuticdevice may function effectively, at least at the one or more treatmentlocations. This may include maintaining mechanical, thermal, or anyother type of contact between the therapeutic device 410 and the wall414. In some illustrative embodiments, the support structure 402 may beconfigured such that the therapeutic device 410 is moved out of contactwith the wall 414 between treatment locations, and in contact only attreatment locations. In some illustrative embodiments, FBG sensors maybe provided proximal (with a specified positional relationship) to someor all treatment locations such that the FBG sensor may providemeasurements related to the therapy. In some illustrative embodiments,at least one FBG sensor is provided proximal to each treatment location.In some illustrative embodiments, the therapeutic device 410 is anablation tip, and the support structure 402 may be configured such thatthe ablation tip ablates tissue within a specified distance of a FBGtemperature sensor. The specified distance may be about 1, 2, or 3 mm.The specified distance may be within an effective ablation radius of theablation tip, which may be about 3 mm.

Systems and methods for optical fiber-based sensing can provide robustreal-time in vivo measurement capabilities for medical procedures. Forexample, in a system like that of FIGS. 3 and 4, therapeutic device 312,410 may be an RF ablation tip and the FBG sensors 306/406 may betemperature sensors. Having a real-time temperature sensor proximal to atreatment location may allow a clinician to verify that ablation energyis being delivered to tissue as intended, for example, by observing thatan expected temperature rise is observed. (Similarly, a temperature dropdue to cryo-ablation could be observed.) The combination of temperaturemeasurement capability along with knowledge of the locations of the FBGtemperature sensors may provide the ability to confirm the position ofthe ablation tip. In some illustrative embodiments, a system and/ormethod may use information provided by a FBG sensor for real-timefeedback control of a therapeutic procedure. For example, in an RFablation procedure performed with the apparatus of FIG. 1, a temperaturemeasurement from a FBG temperature sensor may be used as a feedbacksignal for ablation controller 20, which may modulate the electricalenergy delivered to the ablation tip via conductor 18. The energy could,for example, be increased such that it is sufficient to heat tissue toat least a minimum effective temperature for ablation, but also limitedsuch that it does not overheat tissue. A typical ablation temperaturemay be, for example, about 60 degrees Celsius. Temperature resolutionsachievable by FBG temperature sensor system may depend on variousfactors, such as the type of optical read-out mechanism used. In someinstances, resolutions of 0.1 degrees Celsius may be measured. Lowerresolutions, such as 0.5 or 1 degree Celsius, may be obtainable withless costly equipment, and may be sufficient for therapeutic monitoring.

In some illustrative embodiments, an optical fiber-based sensing systemmay include more than one type of FBG sensor on a single optical fiber.For example, a single optical fiber may include both FBG temperaturesensors and FBG pressure sensors. In a renal nerve ablation procedure oranother procedure in which lowering blood pressure is a desired outcome,a FBG pressure sensor could allow a real-time, local blood pressuremeasurement to be made immediately before, during, and after aprocedure. The typical responsiveness of blood pressure to the nerveablation therapy may not be known, but such a pressure sensor couldpermit the response to be characterized in the actual patient undergoingtreatment. In some illustrative embodiments, leaving an optical fiberwith FBG sensors in situ following an ablation procedure is contemplated(perhaps particularly feasible in cases where the fiber and supportstructure are independent of ablation hardware), making longer termmonitoring of blood pressure at a particular vascular locationpracticable. With an optical fiber left in situ, it is contemplated thatablation hardware may be reintroduced into the vessel at a later timefor a follow-up procedure. If the optical fiber is fixed in the originalposition, then it may be possible to obtain precise knowledge variousold and new therapy locations via the fixed FBG sensors.

Fiber optic-based sensor systems may be fabricated without the use ofmetals or other conductors. Accordingly, they may be compatible withmagnetic resonance imaging and other medical procedures for which thepresence of conductors may present issues. Their dependence on opticsfor their operation can eliminate electromagnetic interference (atnon-optical frequencies) as a potential problem.

Other configurations for optical fiber-based sensor systems arecontemplated. FIG. 5 is a schematic illustration of a distal end of arenal nerve ablation system with ablation electrodes 502 that, whendeployed, are maintained in positions spaced-apart from the vessel wall(not shown). In the embodiment of FIG. 5, an optical fiber 504 isattached to and wraps around the device such that FBG temperaturesensors 506 are placed where, upon deployment, they may be disposed inthermal contact with a vessel wall between the wall and each ablationelectrode 502 so that they may be used to monitor temperatures during anablation procedure.

FIG. 6 is a flowchart of an exemplary optical fiber-based temperaturemeasuring method 600, such as may be performed with devices of thepresent disclosure. At 610, an optical fiber with FBG temperaturesensors is deployed in a vessel. At 620, temperatures detected by FBGtemperature sensors are read out over the optical fiber. Optionally, at630, tissue is ablated proximal to one or more FBG temperature sensors.In some other illustrative embodiments, other therapeutic actions may beperformed. Optionally at 640, the ablation equipment is controlled withfeedback (e.g, measured temperatures) from the FBG temperature sensors.In some other illustrative embodiments, other therapeutic actions may becontrolled with feedback from FBG sensors, which may be sensors otherthan temperature sensors.

Those skilled in the art will recognize that the present disclosure maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departure in form anddetail may be made without departing from the scope and spirit of thepresent disclosure as described in the appended claims.

What is claimed is:
 1. A system for providing therapy at and formonitoring a plurality of temperatures at a vessel wall of a vessel of apatient, the system comprising: an optical fiber designed to be deployedalong an extent of the vessel, the fiber including a plurality of fiberBragg grating (FBG) temperature sensors disposed at a plurality ofcorresponding sensor locations along a length of the optical fiber; anoptical read-out mechanism optically coupled to the optical fiber, theoptical readout mechanism configured to transmit light into the opticalfiber and detect light reflected from the plurality of FBG temperaturesensors, the detected light reflected from the plurality of FBGtemperature sensors encoding local temperatures at each of the pluralityof corresponding sensor locations; a therapeutic device capable ofperforming a therapeutic procedure to or through the vessel wall, thetherapeutic device including a plurality of electrodes, wherein eachelectrode is positioned at a sensor location adjacent an FBG temperaturesensor; a support designed to be deployed within the vessel that iscapable of substantially fixing the optical fiber within the vessel; andwherein the optical fiber is attached to the support such that each ofthe plurality of FBG temperature sensors is positioned radially over oneof the plurality of electrodes.
 2. The system of claim 1, wherein thesupport is configured to compact for delivery into the vessel, andexpand for deployment in the vessel.
 3. The system of claim 1, whereinthe support is capable of fixing the plurality of FBG temperaturesensors against the vessel wall such that each of the plurality of FBGtemperature sensors is in thermal contact with the vessel wall at itscorresponding sensor location.
 4. The system of claim 1, wherein thesupport has a helical shape, and the optical fiber follows the helicalshape of the support.
 5. The system of claim 4, wherein the opticalfiber and plurality of FBG temperature sensors are integrally housed bythe support such that the support, optical fiber, and plurality of FBGtemperature sensors present a substantially constant cross-section alonga length of the support.
 6. The system of claim 1, wherein the opticalfiber has a helical region and is designed to be deployed along theextent of the vessel in a helical path.
 7. The system of claim 6,wherein the plurality of FBG temperature sensors are substantiallyequally-spaced-apart along the optical fiber such that, in combinationwith the helical path along which the optical fiber is deployed, theplurality of FBG temperature sensors are capable of being disposedaround the vessel with substantially equal angular displacements betweenadjacent FBG temperature sensors.
 8. The system of claim 7, wherein thesubstantially equal angular displacements between adjacent FBGtemperature sensors are about 90 degrees.
 9. The system of claim 7,wherein the substantially equal angular displacements between adjacentFBG temperature sensors are about 60 degrees.
 10. The system of claim 6,wherein the pitch of the helical region is between about 5 mm to about15 mm.
 11. The system of claim 1, wherein the optical fiber includes atleast one FBG sensor other than the plurality of FBG temperaturesensors.
 12. The system of claim 1, wherein the electrodes are spacedapart circumferentially around the therapeutic device and wherein theoptical fiber is a single element with a helical shape extending aroundthe therapeutic device.
 13. A method for monitoring a plurality oftemperatures at a vessel wall of a vessel of a patient with an opticalfiber having a plurality of fiber Bragg grating (FBG) temperaturesensors, the method comprising: deploying the optical fiber along anextent of the vessel such that the optical fiber is disposed against thevessel wall with the plurality of FBG temperature sensors in thermalcontact with the vessel wall; wherein a helical support is attached tothe optical fiber that maintains the position of the optical fiber inthe vessel and positions the FBG temperature sensors against the vesselwall and wherein deploying the optical fiber along an extent of thevessel such that the optical fiber is disposed against the vessel wallwith the plurality of FBG temperature sensors in thermal contact withthe vessel wall includes deploying the optical fiber along with theintegrated helical support; reading-out temperatures detected by theplurality of FBG temperature sensors with an optical read-out mechanismconfigured to transmit light into the optical fiber and detect lightreflected from the plurality of FBG temperature sensors; and performinga therapeutic procedure with a therapeutic device disposed within thevessel proximal to at least one of the plurality of FBG temperaturesensors, wherein performing the therapeutic procedure includes ablatingtissue with a plurality of electrodes, wherein each of the plurality ofFBG temperature sensors is positioned directly between one of theplurality of electrodes and the vessel wall.